Cluster bomb control circuit



1960 D. E. RHCHARDSON 2,958,234

CLUSTER BOMB CONTROL cmcun Filed June 7, 1957 2 Sheets-Sheet l FlG.l.

(Vi-u) in lNVENTO/P. D. E. RICHARDSON ATTYS.

Nov. 1, 1960 Filed June '7, 1957 D. E. RICHARDSON CLUSTER BOMB CONTROL CIRCUIT 2 Sheets-Sheet 2 FIRING lNlTlATOR':

L i 33 j 2lo I DISPERSAL ACTUATOR 0.25sec. L36 DELAY INVENTOR. D. E. RICHARDSON ATTYS.

United States Patent M CLUSTER BOMB CONTROL CIRCUIT Donald E. Richardson, Chicago, 111., assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Filed June 7, 1957, Ser. No. 664,449

9 Claims. (Cl. 10270.2)

This invention relates generally to a control system, and more particularly to a signal receiving and control circuit for effecting dispersal of a plurality of submissiles carried by an aircraft launched cluster bomb.

More specifically, the control circuit according to the present invention provides a means for determining the submissile dispersal position relative to the ground by detecting and selectively responding to the light flashes produced by a series of pilot submissiles as they strike the ground. When the time interval between the flashes approaches, or becomes less than, a predetermined value, the instant triggering circuit actuates a submissile dispersal actuator.

The aircraft launched cluster bomb with which the instant control circuit is especially adapted for use contemplates the utilization of a plurality of pilot projectiles adapted to be fired at intervals as the cluster bomb travels along its trajectory and, upon ground impact, to emanate a suitable signal, such for example as a photo-flash, or electromagnetic, impulse. The signal is intercepted, or detected by the instant control, or initiating, circuit arranged in the cluster bomb which determines the time intervals between pilot projectile firings. When the time interval between the detected signals becomes less than a predetermined value, the firing of additional pilot projectiles is terminated, and dispersal of the sub-missiles is effected by the initiating circuit according to the present invention. In applications employing the photo-flash pilot projectile, the deleterious effect of extraneous back ground light, such for example as the open sky and gunfire muzzle flash, upon the sensitivity of the instant circuit may be minimized by use of a photo-flash signal predominantly in the ultraviolet wavelength region.

Prior art systems for initiating dispersal of cluster bomb type submissiles, or multiple projectiles, have utilized conventional fuzing arrangements, such for example as the proximity fuze, or plummet devices suspended from a parachute type bomb. Additionally, aerial bomb releasing devices actuable by ultraviolet energy radiation have been heretofore devised and utilized.

Although the prior art systems hereinabove described have, in general, performed satisfactorily, the instant circuit provides advantages over them in that it is more readily adaptable for use in bombs launched at high aircraft speeds and is less susceptible to enemy countermeasure tactics than the heretofore devised bomb dispersal systems. Moreover, the initiating circuit according to the present invention is capable of indicating the slant range to the ground more accurately than was heretofore possible.

' Accordingly, a principal object of the present invention is to provide a new and improved cluster bomb dispersal initiating device.

Another object of the present invention resides in the provision of a control circuit being selectively responsive to the time intervals between successive signals received thereby.

Patented Nov. 1, 1960 Still another object of the present invention is to provide a new and improved photo-flash responsive slant ra'nge indicating device.

A further object of the instant invention resides in the provision of a signal responsive initiating circuit for actu- Iating the submissile dispersal mechanism of a cluster omb.

A still further object of the present invention resides in the provision of a photo-flash signal responsive initiating circuit essentially insensitive to background atmospheric light or to gun fire muzzle flash fired in the vicinity thereto.

Another further object of the instant invention is to provide a cluster bomb triggering system for initiating automatic fire-on-signal sequence for the pilot projectiles, or for reestablishing the sequence in case a signal is lost.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. 1 illustrates in diagrammatically geometric form the fundamental principles of slant distance measurement by means of the photo-flash responsive triggering circuit;

Fig. 2 is a diagrammatic view of the triggering circuit according to the instant invention; and V,

Fig. 3 is a broken away view of a portion of a bomb partly in section showing an arrangement of the pilot projectiles. 9

Referring now more particularly to Fig. 1, let the velocity of the cluster bomb be V and the velocity of a pilot projectile relative thereto, subsequent to release thereof, be u. If the first pilot projectile is fired when the cluster bomb is at the point P and the photoflash signal generated by the projectile upon ground impact thereof at point Q is detected by the instant initiating circuit when the cluster bomb has reached the point P, in its trajectory, the time t for the first pilot projectile to reach the point Q is obtainable,

( n-1Qn1= i- 0 n and,

( n-1 n= tn hence, a practical approximation of the distance of the cluster bomb from the ground along the new tangent line,

or, by substitution of Equations 1 and 2 in 3, there results,

If upon detection of the photo-flash signal by the instant initiating circuit at point P,,, a second pilot projectile is fired from the cluster bomb, the geometry-for this projectile will be similar to that of the first pilot pro jectile, so that,

Considering a point, P not shown, as being the first firing point in a particular, or frozen, sequence of firing $9 v H V P Q and that L is the geometric, mean of (1,0) nQn and n+1= 1t+1Qn1 then,

d n+ n+t Substitution of Equation 4 in Equation 10 results in, (13) L nt and in like maxing Equations 9 and tively,

Then by substitution of Equation 14 for L in Equation 12, andEquations 13 :and 15 for i",, 'n 1 LE, re spectively, in Equation 12, there results, (-16) t =t t or by dividing through by t there results,

' & n

17 a) h'i'l and, by dividing through by :3, there results,

in n-H 1 7b) [112 n may also be considered that,

( n n+1 n+1= n"' n+1 thereby giving,

a n1 (19) n+l 111+ l Equating Equations 17a and 19- then by square-rooting and mverting the resultant thereof, there results,

fifi )-1/2 v s 1 a u+1 and, by transposition,

' 1/2 n+1 ('g+ d In like manner of mathematical operation, there results from Equations 17b and 19,

Finally, by substitution of Equations 13 and 14 into Equation 22 there results,

and by substitution of Equations 14 and 15 into Equation By way of example, application of the hereinbefore developed design equations to a typical aircraft launched cluster bomb situation wherein the cluster bomb velocity V is approximately 760 fps. and the relative pilot projectile velocity is approximately 1500 f.p.s. shows that the deviation from a desired dispersal distance, L, of 300 feet will be less than 25 percent provided a flash signal arrives at the bomb at any time between 0.15 second and 0.25 second after the firing of a corresponding pilot projectile.

The instant initiating circuit for effecting actuation of a cluster bomb dispersal actuator in conformance with the analytical determination hereinbefore disclosed will now be v fully described. The instant circuit, in addition to satisfying the specified analytical requirement also provides forthe automatic sequential firing of the earliest pilot projectile s, at substantially 0.5 second intervals therebyfcompensatin'g. for the initially fired pilot projectiles whose photo flash signal may be beyond the sensitivity range of the instant control circuit. Moreover, as a safety feature, the instant circuit provides means for delaying the firing of the first'pilot projectile for a time period of 1 second subsequent to release, or launching, of the cluster bomb from its carrying aircraft.

1 Referring now more particularly to Fig. 2 of the drawings, the instant circuit is shown as including a componential arrangement of a gas discharge device 11, photocell amplifier 12, a plurality of potential energy sources respectively designated by the reference numerals 13, 14 and 15, an electrical switch 16, a stepping switch relay 17, and a plurality of direct current relays, respectively designated by the reference numerals 18, 19 and 21. Shunting the coils of DC. relays 18, 19 and 21 are capacitors 22, 23 and 24, respectively, these capacitors being of suificient capacity to maintain the relays 18, 19 and 21 energized for0.l5, 0.50, and 0.25 second, respectively, subsequent to thetermination of energization current through the relay coils thereof.

In applications utilizing pilot projectiles 38, as shown, for example, in Fig. 3, from which emanate photo-flash signals primarily in the ultraviolet wavelength region, a suitable light filter 25 is provided for photocell amplifier l2 thereby preventing transmission thereto of other than ultraviolet wavelength signals. By way of example, a filter consisting of quartzglass having silver chemically deposited thereon has been found especially suited for this application.

I The cooperative relationship between the hereinbefore enumerated componential elements of the instant control circuit will be made more apparent by the following operational description thereof.

Upon release of the cluster bomb from its carrying aircraft, electrical switch 16 is actuated to a closed position by conventional means, such for example as a pull wire, not shown, whereupon a positive potential is developed across resistor 26 from battery 13 and transmitted through blocking capacitor 27 to the grid electrode of normalycut-ofi gas tube 11. A grid resistor 28 is provided for the gas discharge device 11. This positive potential' places tube 11 in a conductive condition whereupon a current path through the coil of relay 18 and across capacitor 22 is established.

Prior to firing of gas tube 11, capacitor 22 has been pre-charged from battery 14 through normally closed relay contacts 18a. Firing of gas tube 11 results in the energization of the coil of relay 18 whereupon actuation of relay contacts 18a through 18:: from an initial position to a moved position is initiated. Upon opening of relay contact 18a and closing contact 180, and prior to closure of relay contact 18d, the current through the coil of relay 18 is supplied by discharging pre-charged capacitor 22 therethrough. The completion of the actuation of the contacts of relay 18 to a moved position results in the extinguishment of gas tube 11 by the parallel short current path to ground 29 through now closed relay contact 180. In addition, relays 19 and 21 are energized from source 15 through closed relay contacts 18d and 182, respectively, thereby resulting in the opening of relay contact 19:: and closure of relay contact 21a. Moreover, actuation of relay contact 18b to a moved position deactivates the photocell amplifier 12 by interrupting the energization path thereto from battery 14, and operatively energizes stepping switch relay 17 by completing the circuit path thereto from battery 15. Energization of relay 17 actuates wiper 31 from its initial position on stationary contact a to stationary contact b. However since no connection is made to stationary contact b, the energization or triggering circuit 32 of the pilot projectile firing initiator 33 is retained inefiective and no pilot projectiles will be fired at this time. By the continuous discharge of capacitor 22 through the resistance of coil 18 and its parallel resistor 34, relay contacts 1811-482 are maintained in their moved positions for a 0.15 second time interval as indicated, subsequent to the extinguishment of gas tube 11. Resistance 34 is connected in shunt across the coil of relay 18 to minimize the inductive voltage efiect thereof. A consideration of the hereinbefore described operational sequence will make it apparent to one skilled in the art that since the photocell amplifier is deactivated for substantially 0.15 second after energization of relay 18 and that upon deenergization of relay 18, with the attendant reactivation of the photocell amplifier, the circuit 35 to theelectroresponsive submissile dispersal actuator 36, or any other similar utilization device, is only maintained continuous by relay contact 21a for a time interval of 0.25 second, by the action of capacitor 24, and dispersal of the submissiles can only be effected by reception of a photo-flash signal at t occurring during the time interval 0.15 t 0.25 second. Of course, since no pilot projectile has yet been fired, no photo-flash signal can occur at this stage of operation during this time interval. When no signal has been detected by the photocell amplifier 12 for 0.5 second, a second positive impulse is impressed upon the control grid of gas tube 11 from battery 13 by the effect of shunting capacitor 23 in delaying the return of relay contact 19:: to its initial closed position subsequent to the deenergization of relay 18. This operation results in the firing of gas tube 11 and actuation of relay 18 with the consequent repetition of the hereinbefore described operational sequence, including movement of wiper 31 to stationary contact 0 of the stepping switch relay. As in the case of stationary contact b, since no electrical connection is made to stationary contact 0, pilot projectile ejector 33 will not fire a pilot projectile from the cluster bomb.

Upon the expiration of the next 0.5 second time interval, the hereinbefore sequential operation of the instant control circuit will again be repeated with a consequent movement of Wiper 31 to stationary contact d. Inasmuch as contact d, as well as the remaining stationary contacts of stepping switch relay 17 is electrically connected to actuating circuit 32, the pilot projectile ejector 33 fires the first pilot projectile. It will be appreciated that by not including stationary contacts b and c in circuit 32, the desired 1 second pilot projectile firing delay is obtained.

Subsequent actuation of stepping switch 17 will result in the sequential firing of pilot projectiles at 0.5 second time intervals until detection of a photo-flash signal by the photocell amplifier 12 in the time interval of Signal reception during this time interval will result in the generation of a suitable triggering impulse by the photocell amplifier which is transmitted through capacitor 37 to the gas tube 11 whereupon firing of another pilot projectile will be immediately eifected. In all such instances,

the generated triggering signal will not actuate dispersal actuator 36 since lead 35 thereto will be interrupted by relay contact 21a. Eventually, however a photo-flash signal indicative of pilot projectile ground impact will be detected by photocell amplifier 12 during the time interval of 0.l5 t 0.25 second whereupon the triggering signal developed by amplifier 12 of the instant initiating circuit in response thereto will effect ignition of the submissile dispersal actuator 36 by transmission of the signal thereto across lead 35 and closed relay contact 21a.

It will be apparent to one skilled in the art that the time periods hereinbefore indicated are by way of example, and not limitation, and may be readily varied to suit divers applications and operational conditions.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A control circuit comprising a plurality of launchable signal emanating means, first circuit means adaptable to being sequentially energized for effecting launching of said signal emanating means, second circuit means adaptable to being sequentially energized for detecting the signal from said signal emanating means and for developing an output signal in response thereto, third circuit means adaptable to being energized upon energization of said first circuit means for effecting transmission of said output signal to a utilization means, and fourth circuit means for normally rendering said first circuit means sequentially energized at a predetermined repetition rate and upon development of said output signal during a preselected time period for rendering said first circuit means energized at a repetition rate correlative to the rate of development of said output signal.

2. A control circuit comprising a plurality of launchable signal emanating vehicle, normally deenergized, first circuit means adaptable to being sequentially energized for effecting individual launching of said signal emanating vehicles, second circuit means adaptable to being energized for a predetermined time interval upon deenergization of said first circuit means for receiving a signal from the launched signal emanating vehicles and for developing an output initiating signal in response thereto, normally deenergized third circuit means adaptable to being energized for a predetermined time interval upon energization of said first circuit means for transmitting said initiating signal to a utilization means, and fourth circuit means for normally rendering said first circuit means sequentially energized at a preselected repetition rate and in response to an output signal developed during the deenergized intervals of said third circuit means for rendering said first circuit means energized at a repetition rate correlative to the rate of development of said initiating signal.

3. A control circuit comprising a plurality of launchable signal emanating device, normally deenergized first circuit means adaptable to be sequentially energized for eifecting individual launching of said signal emanating devices, second circuit means adaptable to being energized upon deenergization of said first circuit means for a first preselected time interval for detecting a signal from the launched signal emanating devices and for developing an initiating signal in response thereto, normally deenergized third circuit means adaptable to being energized for a second preselected time interval upon energization of said first circuit means for transmitting said initiating signal to a utilization device, said second time interval occurring during a predetermined portion of said first time interval, and fourth circuit means for normally energizing said first circuit means at a predetermined sequential rate and in response to an output signal developed during the deenergized interval of said thirdcircuit means for rendering said first circuit means energized at a sequential rate correlative to the rate of development of said initiating signals. 7

4. A control circuit for a utilization device comprising a multiplicity of launchable devices each of which emanates a signal upon impact, normally deenergized first circuit means adaptable to being sequentially energized for effecting sequential launching of said signal emanating devices subsequent to apredetermined number of energizations thereof, second circuit means adaptable to being sequentially energized for a first preselected time interval for detecting a signal from a launched signal emanating device and for developing an initiating signal in response thereto, normally deenergized third circuit means adaptable to being energized for a second preselected time interval upon energization of said first circuit means for transmitting said initiating signal to the utilization device, a predetermined interval of said first and second preselected time intervals being concurrent, and fourth circuit means for normally energizing said first circuit means at a predetermined sequential rate and upon development of an initiating signal during the deenergized intervals of said third circuit means at a sequential rate correlative to the rate of development of said initiating signals. I

5. A control circuit according to claim 4 wherein said first circuit means includes a stepping switch relay having a predetermined number of preliminary contact positions which are ineffective in said sequential launching operation.

6. A control circuit according to claim 4 wherein said second circuit means includes an amplifier responsive to a particular signal frequency band.

7. A control circuit according to claim 4 wherein said third circuit means includes an electroresponsive relay, and energy storage means for maintaining said relay energized for said second preselected time interval.

8. Acontrol circuit according to claim 4 wherein said fourth circuit means includes first energy storage means, normally nonconductive gas discharge means being adapted to be connected to said storage means thereby to be rendered conductive, normally deenergized first electroresponsive relay means serially connected to said gas discharge means, said relay means being energized upon said gas discharge means being rendered conductive,

second energystorage means for maintaining said relay means energized for a predetermined time interval after saidgas discharge means is rendered nonconductive, and normally deenergized, second electi'oresponsive relay means normally interconnecting said gas discharge-means and said first energy storage means, said second relay means being energized in response to the energization of said first relay means thereby interrupting the connection betweensaid gas discharge means and said first storage means, and third energy storage means for maintaining said second relay means energized fora predetermined time interval subsequent to the deenergization of said first relay means.

9. In a cluster bomb having a dispersal actuator for discharging a plurality of explosive submissiles, a control circuit comprising a plurality of pilot projectiles emanating a signal upon ground impact, ejector means for effecting individual launching of said pilot projectiles, normally deenergized first circuit meansbeing sequentially energizable for effecting launching of said pilot projectiles by said ejector means subsequent to a predetermined number of energizations thereof, second circuit means being sequentiallyenergizable for a preselected timeinterval for developing an initiating signal in response to a signal from a launched pilot projectile, normally deenergized third circuit means being energizable for a preselected time interval upon each energization of said first' circuit means for transmitting said initiating signal to the dispersal actuator, the preselected time interval of said third circuit means occurring during a predetermined portion of the preselected time interval of said second circuit means, and fourth circuit means for normally energizing said first circuit means at a preselected uniform sequential rate and in response to an initiating signal developed during the deenergized interval of said third circuit means for subsequently rendering said first circuit means energized at a sequential rate correlative to the rate of development of said initiating signals.

References Cited in the file of this patent 4 UNITED STATES PATENTS 2,404,942 Bedford July 30, 1946 2,432,920 McKay Dec. 16, 1947 2,441,030 Page May 4, 1948 2,557,949 Deloraine June 26, 1951 

